I would say low to moderate value. Yes, it does stand for e-ink. However, it is unlikely that any tech product manufacturers would attempt to market their products under "e-ink" as a brand, they will use their own brand names and use e-ink as a product description.
Actually, I have just checked and it looks like Eink may be trademarked. This makes it a proprietary term and not a generic term and would detract from domain value.